Lunch box



FIG. 1 is a perspective view of a lunch box showing my new design;

FIG. 2 is a front elevation view thereof;

FIG. 3 is a back elevation view thereof;

FIG. 4 is a left side view thereof;

FIG. 5 is a right side view thereof;

FIG. 6 is a top plan view thereof;

FIG. 7 is a bottom plan view thereof; and,

FIG. 8 is a perspective view thereof in an open state.

The broken lines in the drawing depict portion of the lunch box only and form no part of the claimed design. 

CLAIM The ornamental design for a lunch box, as shown and described. 